ValueError: This scheme is not supported: {<Prefix.I: 1>, <Prefix.B: 4>, <Prefix.S: 16>, <Prefix.O: 2>}

[Lowryyyy]

traing过程中出现这个问题，原因是什么呢？
Traceback (most recent call last):
File "C:\Users\lenovo\Desktop\BERT-NER-Pytorch-master (1)\BERT-NER-Pytorch-master\run_ner_crf.py", line 561, in
main()
File "C:\Users\lenovo\Desktop\BERT-NER-Pytorch-master (1)\BERT-NER-Pytorch-master\run_ner_crf.py", line 496, in main
global_step, tr_loss = train(args, train_dataset, model, tokenizer)
File "C:\Users\lenovo\Desktop\BERT-NER-Pytorch-master (1)\BERT-NER-Pytorch-master\run_ner_crf.py", line 176, in train
results = evaluate(args, model, tokenizer)
File "C:\Users\lenovo\Desktop\BERT-NER-Pytorch-master (1)\BERT-NER-Pytorch-master\run_ner_crf.py", line 277, in evaluate
logger.info(classification_report(y_true, y_pred, digits=4, mode='strict'))
File "C:\Users\lenovo\Desktop\BERT-NER-Pytorch-master (1)\BERT-NER-Pytorch-master.venv\lib\site-packages\seqeval\metrics\sequence_labeling.py", line 670, in classification_report
return cr(y_true, y_pred,
File "C:\Users\lenovo\Desktop\BERT-NER-Pytorch-master (1)\BERT-NER-Pytorch-master.venv\lib\site-packages\seqeval\metrics\v1.py", line 381, in classification_report
scheme = auto_detect(y_true, suffix)
File "C:\Users\lenovo\Desktop\BERT-NER-Pytorch-master (1)\BERT-NER-Pytorch-master.venv\lib\site-packages\seqeval\scheme.py", line 352, in auto_detect
raise ValueError(error_message.format(prefixes))
ValueError: This scheme is not supported: {<Prefix.I: 1>, <Prefix.B: 4>, <Prefix.S: 16>, <Prefix.O: 2>}